THE NEW YORK JOURNAL OF PHARMACY 



15 



containing 2% of water. The sodium 

 compounds of the fatty acids are sol- 

 uble to the extent of less than 2% in 

 the same solvent. 



The authors suggest a method based 

 on this difference in solubility. The 

 substances to be examined may con- 

 sist of mixtures of resins and fatty 

 acids, or of mixtures of resins with 

 sodium soaps, glycerine however must 

 be absent. 



2 grammes of the fatty mixture lOr 

 3 grammes of resin and soap, accur- 

 ately weighed are placed in a nickel 

 crucible and dissolved in 15 to 20 ccm. 

 of alcohol. After adding phenol- 

 phthalein solution, the mixture is ex- 

 actly neutralized, by carefully adding 

 an alcoholic solution of sodium hy- 

 droxide. The liquid is then evapo- 

 rated on an as]>estos plate, until a pel- 

 licle forms. 



10 grammes of sharp, clean sand are 

 then added, the whole thoroughl}' 

 mixed by means of a pestle, and the 

 vaporization continued, under constant 

 stirring, until all alcohol has been re- 

 moved. The residue is allowed to 

 cool, and then thoroughly dried in a 

 drying oven. 



The dry residue is now extracted 

 with acetone containing 2% of water. 

 Commercial acetone is treated with 

 burnt sodium sulphate, until thorough- 

 ly dried and then 2% of distilled water 

 added, about 100 ccm. of the reagent 

 will be a sufficient quantity. 



The extraction is carried out with 

 8 successive portions uf 10 ccm. each 

 of acetone. The liquid is thoroughly 

 mixed with the residue, by aid of a 

 pestle, in each instance, and the clear 

 liquid decanted. The decanted liquids 



are collected in a beaker and allowed 

 to stand. If any solid material sep- 

 arates out this is removed by filtra- 

 tion, and the filter washed with ace- 

 tone. The filtrate and washings are 

 now concentrated on the water-bath 

 to one-half of the original volume, 

 when the liquid should remain clear. 

 In the event of a further separation of 

 solids, these should again be removed 

 by filtration. After this the rest of 

 the acetone-water mixture is removed 

 bv evaporation, and the residue thor- 

 iiughlv dried and weighed. 



A. Jonsson, in Farmaceutisk Revy. 

 1913, No. 49, calls attention to the 

 variable composition of PASTILLES OF 

 MERCURIC CHLORIDE. He exam- 

 ined a number of samples obtained on the 

 market, each of which was required to 

 contain a definite quantity of mercuric 

 chloride. 



The method employed was as fol- 

 lows: 



One pastille was dissolved in 100 

 ccm. of distilled water, and the re- 

 sulting solution filtered. 20 ccm. of the 

 filtrate were treated with s ccm. of 

 hvdrochloric acid, and 100 ccm. of a 

 saturated aqueous solution of hydro- 

 gen sulphide, heated and filtered. 



The precipitate was thoroughly 

 washed, and together with the filter 

 was transferred to a glass-stoppered 

 flask, taking care th'at none of the 

 precipitate remained in the vessel in 

 which the precipitation took place. 



To the contents of the flask was 

 added first 20 ccm. of distilled water 

 and then 25 ccm. of deci-normal iodine 

 solution, and the whole shaken thor- 

 ougfhlv for several mimites. 



